BRUSSELS, Belgium - Days after more than 150 countries, including Belgium backed a United Nations Migration pact, the Belgian capital witnessed violent protests against the non-binding deal.

The UN Global Compact for Migration, which is aimed at managing migrant flows internationally, was agreed by 193 members of the United Nations, except the United States in July this year.

However, last week, at an intergovernmental UN conference held in Marrakesh, Morocco - 164 countries formally signed the 'Global Compact for Safe, Orderly and Regular Migration pact' agreeing on an effective, international framework on migration.

Political jeopardy

The Belgian Prime Minister Charles Michel's decision to back the UN pact last week caused the biggest party in his governing coalition - the New Flemish Alliance (N-VA) - to quit the coalition.

While all the four parties in Belgium's coalition supported the UN pact initially, the Flemish nationalist N-VA and the far-right Vlaams Belang party voted against it in October.

Ignoring warnings from both the parties last week, Michel formally signed the pact, causing the N-VA to exit the coalition.

The decision by the N-VA, which held four top positions in the country's parliament, including the post of Defense Minister, Interior Minister, State Secretary for Asylum Policy and Migration, plunged the government into chaos, five months before legislative elections.

Protesting Michel's backing for the pact, which the party believes could increase immigration to Europe, the N-VA pulled its ministers from the ruling coalition.

'Outburst of anger and violence'

In a bid to express their opposition over the UN accord more strongly, right-wing and far-right Flemish associations in the country rallied supporters to stage a march in Brussels on Sunday.

Thousands of people responded to calls by the Flemish parties, participating in the protest, which led to clashes in the capital.

According to officials in Brussels, about 5,500 demonstrators congregated near major EU institutions in the city, with many holding placards and posters with slogans like 'Our people first' and 'We have had enough, close the borders.'

Reports noted that a majority of the protesters were supporters of the harder-right, anti-immigration Vlaams Belang party, which had also warned Michel against signing the UN pact.

The protest, which was initially banned by local authorities over fears of violence, received a clearance from Belgiums high court, which cited the right to protest peacefully for overturning the ban.

However, the anti-migration protest turned violent when demonstrators reportedly tried to storm the European Commission building.

Local reports quoted officials as saying that over 5,000 protesters clashed with heavily-armed police outside the EU headquarters.

Police teams tried to block protesters from entering the Berlaymont headquarters of the European Commission by firing water cannons and tear gas at the crowd, but were reportedly attacked with rocks.

A report in De Morgen said that some protesters hurled rocks, fire crackers and projectiles at the police, while others smashed windows of the European Commission building.

According to the police in Brussels, around 90 people were detained by the end of the protest.

Following the violent clashes, Mayor Philippe Close took to Twitter and wrote, "Thanks to the police services for having again assured today the public order in our beautiful [city]."

Meanwhile, anti-immigration protesters were also challenged by a smaller number of counter-demonstrators in the capital, with about 1,000 people staging a rally to oppose the right-wing march.

The non-binding agreement among the majority of UN member states to cooperate in ensuring safe and orderly migration and upholding the rights of migrants around the world - was signed at a time when 'migration' has become the top most divisive issues across Europe.

While conservative and far-right voices across the world have warned that it threatens national sovereignty, the Pact received support from Pope Francis on Sunday.

The pontiff urged the international community to show responsibility, solidarity and compassion in dealing with migrants and asserted that the UN pact was designed to secure safe, ordered and regular migration.

So far, ten countries, including the U.S., Austria, Hungary, Italy, Poland and Slovakia, have pulled out of the non-binding pact.